Ecosystem services-based composite indicator for assessing community resilience to floods

Abstract

Disaster resilience studies have acknowledged the role of the natural environment in reinforcing community resilience; however, pragmatic environmental indicators are lacking, particularly geospatial composite indicators. This paper aims to introduce a composite environmental indicator for assessing community resilience to floods, targeting regional-scale geospatial applications. The composite indicator has been built on conceptualized inter-relationships between Ecosystem Services (ESs) and community resilience. The environmental parameters used to measure the composite were identified by surveying the cross-disciplinary literature from the domains of ESs and disaster resilience. The application of the composite indicator was demonstrated by a case study in Colombo, Sri Lanka. The composite indicator was tested on flood declaration and community response data from Colombo. The application employed a Weighted Linear Combination Method (WLCM) and was executed in a Geographic Information System (GIS)-based platform. The geospatial data for application and validation were collected through secondary sources. The developed composite indicator consists of four proxy indicators (i.e., soil hydraulic properties, slope, land use, and a precipitation factor) and parameters used to measure them. The parameters were also derived from the conceptualized relationship that elaborates ESs into a bundle of services, including flood regulation, climate regulation, and nutrient recycling, whereas many of the existing resilience assessment methodologies focused only on flood regulation. Furthermore, the composite indicator organized the environmental parameters into two tiers, facilitating a range of users. Hence, incorporating this ESs-based composite indicator into existing resilience assessment methodologies could guide community resilience-building initiatives towards more sustainable outcomes.